Experimental interrogations on morphologies and mechanical delineation of silicon nitride fortified Mg-Al-Zn alloy composites

The smart material used in aerospace and automotive industries has to withstand high load with minimum structural weight. Nowadays, in search of new lightweight materials for the industrial application, magnesium is rapidly replacing aluminium-based alloys. In this research, magnesium (AZ31) matrix composite reinforced with ceramic silicon nitride (Si3N4) particle is fabricated by vacuum stir casting. The proportion of strengthening particle was assorted to a maximum of 10 % in steps of 2 % variation in weight. Microstructural analysis carried out through optical microscope exposes the occurrence and near-uniform spread of Si3N4. The mechanical properties for various weight proportions are studied; microhardness and strength are enhanced at the expense of ductility reduction with rising Si3N4 content in the magnesium metal matrix. The porous nature and composites density rises with higher weight % of Si3N4 particles in the magnesium matrix. The corrosion characteristic was studied by salt spray and cyclic potentiodynamic polarization test, which demonstrates that increasing the reinforcement limits the corrosion by forming phases of Mg2Si intermetallics with galvanic corrosion mechanism. The inferences present that the fabricated composite are ideal for many industrial plans where less structural weight material is required.